Electrostatically atomizing unit for use in a temperature-regulating appliance

ABSTRACT

An electrostatically atomizing unit for use in a temperature regulating appliance to add a function of generating a mist of charged minute water particles for deodorization and/or sterilization of a temperature-regulated space. The appliance has a cold space of which air is cooled by cooling means and is fed to cool the temperature-regulated space divided from the cold space by a partition. The atomizing unit has an emitter electrode which is configured to condense water from within a surrounding air. A high voltage source applies a high voltage to the emitter electrode to atomize the condensed water into the charged minute water particles which are discharged from the emitter electrode into the temperature-regulated space. The emitter electrode is provided with a cooling coupler which establishes a heat transfer relation through the partition to the cold space to cool the emitter electrode by making the use of the cooling means inherent to the appliance.

TECHNICAL FIELD

The present invention is directed to an electrostatically atomizing unitfor use in a temperature-regulating appliance, such as a refrigerator,an air conditioner, or the like appliance, to add a function ofgenerating a mist of charged minute water particles.

BACKGROUND ART

Japanese patent publication no. 2006-68711 discloses anelectrostatically atomizing unit capable of generating a mist of chargedminute water particles. The unit is specifically configured to condensewater from within an atmosphere and atomize the condensed water into themist of the charged minute water particles. For this purpose, theatomizing unit includes a cooling means of cooling an emitter electrodeso as to condense the water on it, which eliminates a need of providinga tank holding the water and a mechanism of feeding the water from thetank to the emitter electrode. In this regard, the prior atomizing unitcan be successfully incorporated in an appliance or vehicle to add thefunction of generating the mist with an accompanied effect ofdeodorization and/or sterilization. However, since the unit necessitatescooling module such as realized by a Peltier-effect module to condensethe water and supply the water to the emitter electrode, the coolingmodule itself adds an extra bulk to the appliance when the unit isincorporated in the appliance, especially when the unit is incorporatedin the appliance such as a refrigerator or air conditioner inherentlyequipped with cooling means which could be utilized to cool the emitterelectrode.

DISCLOSURE OF THE INVENTION

In view of the above problem, the present invention has beenaccomplished to provide an electrostatically atomizing unit which can beincorporated into a temperature-regulating appliance to add a functionof generating a mist of charged minute water particles, yet at a minimumspace and cost requirement. The appliance includes a housing configuredto have a temperature-regulated space and a cold space divided by apartition, and includes cooling means for cooling the cold spacerelative to the temperature-regulated space to provide a temperaturedifference therebetween so as to regulate a temperature of thetemperature-regulated space by a cold air from the cold space. Theatomizing unit includes an emitter electrode which is configured tocondense water thereon from within surrounding air when being cooled.The unit includes a high voltage source which is configured to apply ahigh voltage to the water on the emitter electrode for electrostaticallycharging the water and atomizing it into the mist of the charged minutewater particles at a front end of the emitter electrode. The emitterelectrode is configured to have its front end exposed to thetemperature-regulated space and to have its opposite rear end held inheat transfer relation with the cold space through the partition so asto be cooled by the cold space for condensing the water on the emitterelectrode. With this arrangement, the atomizing unit can utilize thecold air in the cold space for condensing the water on the emitterelectrode, and can dispense with a dedicated cooling system, whichenables to add the function of generating the mist to the appliance, yetwith a minimum structural and space requirement.

Preferably, the atomizing unit include a casing which is configured toaccommodate the emitter electrode and the high voltage source. Thecasing has a front wall and a rear wall spaced from each other, and ismounted on the partition with the rear wall in contact with thepartition. The front wall is formed with an outlet for introducing theair from the temperature-regulated space as well as discharging the mistinto the temperature-regulated space. The emitter electrode is providedwith cooling coupler which projects out through the rear wall into thepartition. The cooling coupler can provide a thermal bridge from thecold space to the emitter electrode for effectively cooling the emitterelectrode sufficient to condense the water thereon. Thus, the atomizingunit can be easily incorporated in the appliance simply by being mountedon the partition, yet making the best use of the cold air in theappliance for cooling the emitter electrode.

The partition may be partly formed with a reduce-thickness portion whichreceives the projecting end of the cooling coupler. In this instance,the cooling coupler can have its projecting end close to the cold spacefor effectively cooling the emitter electrode. The reduced-thicknessportion can be realized by a recess formed in the surface of thepartition so that the recess can be well utilized to position theatomizing unit on the partition for easy mounting.

Most preferably, the atomizing unit includes an opposed electrode heldin an opposite relation with the front end of the emitter electrode, andis connected to receive the high voltage with the emitter electrodebeing connected to a potential nearer to a ground potential than theopposed electrode. Thus, the partition or the housing of thetemperature-regulating appliance can be free from the high voltage toavoid high voltage hazard.

Further, the atomizing unit may additional include a heating jacketwhich is held in heat transfer relation with the emitter electrode andis configured to heat the emitter electrode. In this connection, theatomizing unit includes a controller which is configured to detect atemperature difference between the cold space and the temperatureregulated space and to activate the heating jacket only when thetemperature difference exceeds a critical level. Thus, the emitterelectrode is protected from being over-cooled, and therefore free fromfreezing of the water on the emitter electrode, enabling to keepgenerating the mist.

Alternatively, the emitter electrode may be configured to project itsrear end out through the ear wall into the partition to establish a heattransfer relation with the cold space through the partition foreffectively cooling the emitter electrode to condense the water thereon.In this instance, the emitter electrode is preferred to be surrounded bya cooling jacket which has a larger volume than the emitter electrode toserve as a thermal accumulator in order to keep cooling the emitterelectrode at a desired temperature for successively and stablycondensing the water.

These and still other advantageous features of the present inventionwill become more apparent from the following description of a preferredembodiment when taken in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of a refrigerator, a typical one ofa temperature regulating appliance which incorporates anelectrostatically atomizing unit of the present invention;

FIG. 2 is a sectional view of the electrostatically atomizing unitutilized in the above temperature regulating appliance;

FIG. 3 is a sectional view illustrating a portion of the atomizing unit;

FIG. 4 is a schematic diagram illustrating a mist of charged minutewater particles generated by the atomizing unit;

FIG. 5 is a sectional view illustrating a portion of a modifiedatomizing unit; and

FIG. 6 is a sectional view illustrating a portion of an atomizing unitin accordance with another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to FIGS. 1 to 3, there is shown a temperature regulatingappliance incorporating an electrostatically atomizing unit 50 ofgenerating a mist of charged minute water particles in accordance with apreferred embodiment of the present invention. In the illustratedembodiment, a refrigerator 10 is shown as a typical example of theappliance inherently equipped with the cooling means of generating acold air. The present invention is not limited to the use for thisparticular example, and may be utilized for an air conditioner or thelike equipped with the cooling means, and an associated structure with acold space cooled by the cooling means and at least one temperatureregulated space in heat transfer relation with the cold space.

As shown in FIG. 1, the refrigerator 10 includes a housing 20 dividedinto the cold space 30 and a plurality of temperature-regulated spaces,namely, freezer room 22, a vegetable storage room 24, and a fresh room26. These rooms are separated respectively by partitions 42, 44, and 46from the cold space 30 which is supplied with the cold air generated ata cooling device 32 and is blown by a fan 34. For example, the cold airgenerated and flowing in the cold space 30 is maintained at atemperature of −20° C. The cold air is fed into the individual roomsrespectively through restricted openings 43, 45, and 47 for cooling therooms, for example, the vegetable room 24 to a temperature of +5° C.,the freezer room 22 and the fresh room 26 to temperatures of −15° C. and+7° C., respectively. In this sense, each of the rooms can be referredto as a temperature regulated space. The atomizing unit 50 is mounted onthe partition 44 separating the vegetable room 24 from the cold space 30to discharge the mist into the vegetable room 24 for deodorizing and/orsterilizing the vegetable room 24 and contents stored therein.

As shown in FIG. 2, the atomizing unit 50 includes a flat rectangularcasing 60 with a front wall 61 and a rear wall 62 spaced from each otherto define therebetween a mist chamber 70 and a driver chamber 72 whichis hermetically closed chamber separated from the mist chamber 70 by adividing wall 71. The bottom wall 62 has an opening 65 for detachablyreceiving a frame 80 which carries an emitter electrode 52 projectinginto the mist chamber 70 towards an outlet 64 formed in the front wall61. An opposed electrode 54 of ring-shape is supported to the front wall61 around the outlet 64 in an opposed relation to the front end of theemitter electrode 52. The casing 60 and the frame 80 are made of adielectric plastic material, while the emitter electrode 52, and theopposed electrode 54 are made of an electrically conductive metallicmaterial. As best shown in FIG. 3, the emitter electrode 52 has its rearend connected to and surrounded by a cooling coupler 90 which is made ofa metal having a good thermal conductivity into a cylindrical shapefitted within the center of the frame 80. The cooling coupler 90 isformed in its front end with a cavity 92 through with the emitterelectrode 52 projects with its rear end embedded into the coolingcoupler 90 and with a middle portion being spaced from a side wall ofthe cavity 92. The cooling coupler 90 has its rear end projecting outthrough the rear wall 62 of the casing 60 to establish a thermal bridgebetween the cold space 30 and the emitter electrode 52 for cooling theemitter electrode 52 by making the use of the cold air flowing in thecold space 30, thereby condensing water from within surrounding air soas to constantly supply the water on the emitter electrode 52.

The atomizing unit 50 includes a high voltage source 74 which applies ahigh voltage between the emitter electrode 52 and the opposed electrode54 to atomize the water on the emitter electrode 52 into the chargedminute water particles and therefore generate the mist of the particlesfrom the front end of the emitter electrode 52 towards and through theopposed electrode 54, thereby discharging the mist through the outletport 64 out of the casing 60 into the vegetable room 24. The highvoltage source 74 is controlled by a controller 76 to apply the highvoltage at a controlled manner for generating and discharging the mistinto the vegetable room 24 continuously or at variable intervals. Inthis connection, the emitter electrode 52 is fitted with a terminal 53on the bottom of the cavity 92 for electrical connection with the highvoltage source 74, while the opposed electrode 54 is provided on itsouter periphery with a terminal 55 for electrical connection with thehigh voltage source 74. The high voltage source 74 and the controller 76are accommodated within the driver chamber 72 isolated from the mistchamber 70.

In the present embodiment, the high voltage source 74 is configured toapply 5 kV to the opposed electrode 54 with the emitter electrode 52being held in a ground potential or 0 V, so as to generate negativelycharged minute water particles having a diameter in the order ofnanometers at the front end of the emitter electrode 52. In detail, thehigh voltage difference causes the water at the tip of the emitterelectrode 52 to develop a Taylor cone (T), as shown in FIG. 4. As theTaylor cone develops, the electric charge becomes concentrated to a tipof the cone to thereby further increase electric field strength, whichcauses the cone to grow further with increased concentration of thecharge at the tip of the cone. With this consequence, an increasedenergy is applied to the tip of the cone to cause Rayleighdisintegration to atomize the cone into the charged minute waterparticles in the order of nanometers.

Although such high voltage difference also causes the emitter electrode52 to generate negative ions, the negative ions are inherently ofextremely less weight than the charged minute water particles, and canbe easily seized by the positively charged opposed electrode 54. Withthis result, as schematically shown in FIG. 4, most of the negative ions(I) moving along electric flux lines (φ) are adhered on the opposedelectrode 54, allowing only a minimum number of the negative ions toreach the vegetable room 24 and contents (C) stored therein, thuskeeping the vegetable room and the contents from being excessivelycharged, and therefore minimizing an electrostatic shock experienced bya user. On the other hand, the negatively charged minute water particles(W) are driven to move through the opposed electrode 54 because of itsrelatively large mass and therefore of large inertia force, therebyreaching and adhering on the wall of the vegetable room 24 as well asthe contents (C) stored therein for effective deodorization andsterilization.

Turning back to FIGS. 2 and 3, the atomizing unit 50 is mounted on thepartition 44 with its rear wall adhered thereto to communicate theoutlet 64 with the interior of the vegetable room 24 for introducing theair of the vegetable room 24 into the mist space 70 as well asdischarging the mist into the vegetable room 24. The partition 44 isformed in its surface opposing the vegetable space 24 with a recess 48which inturn forms a reduced-thickness portion in the partition 44. Therear end of the cooling coupler 90 is fitted in the recess 48 and comesinto a heat transfer relation with the cold space 30 through thereduced-thickness portion so as to establish the thermal bridge betweenthe cold space 30 and the emitter electrode 52. The depth of the recess48 is selected to give an optimum temperature difference between thecooling coupler 90 and the cold space 30 sufficient for cooling theemitter electrode 52 while keeping an intended thermal insulationbetween the cold space 30 and the vegetable room 24. However, it may bepossible to project the rear end of the cooling coupler 90 into the coldspace 30 for direct heat transfer relation to the cold air in the coldspace 30, where the emitter electrode 52 is not cooled excessively bythe cold air, i.e., cooled to a temperature of freezing the water on theemitter electrode 52. The partition 44 is made of a thermally insulatingmaterial and is covered with a sheath 45 except at the recess 48.

As shown in FIG. 3, the cooling coupler 90 is shaped to have a largervolume or thermal capacity than the emitter electrode 52 so as to keepcooling the emitter electrode for successive condensation of the waterthereon. The water is condensed on a middle portion of the emitterelectrode 52 exposed in the cavity 92 of the cooling coupler 90 and onthe front end projecting from the cooling coupler 90. The middle portionis confined by the side wall of the cavity 90 in a spaced relationtherefrom and can be cooled also from the surrounding wall of the cavity92. The high voltage source 74 and the controller 76 are isolated awayfrom the cooling coupler 90, and accommodated within the driver chamber71 separated from the mist chamber 70 so as to be protected from themist as well as being cooled, and therefore being made moisture-free forreliable electrical operation over a long period of use.

FIG. 5 shows a modification of the atomizing unit which is additionallyprovided with a heating jacket 100 disposed on the rear end of the frame80 to surround the cooling coupler 90 between the partition 44 and theframe 80. The other configurations are identical to the aboveembodiment. Therefore, like parts are designated by like referencenumerals, and no duplicate explanation is made herein. The heatingjacket 100 is introduced to heat the cooling coupler 90 when the coolingcoupler 90 is over-cooled to such an extent of condensing excessiveamount of water or freezing the water on the emitter electrode 52. Forthis purpose, the atomizing unit 50 includes a first temperature sensor101 provided on the partition 44 for sensing temperature of the coldspace 30, a second sensor 102 and a humid sensor 103 respectivelyprovided on the front wall 61 for sensing temperature and humidity ofthe vegetable room 24. Outputs of these sensors are received at thecontroller 76 which is configured to determine an optimum temperature towhich the emitter electrode 52 is cooled for condensing sufficientamount of water to generate the mist successfully, and to keep thetemperature of the cooling coupler 90 around the optimum temperature byactivating the heating jacket 100.

During the operation of the refrigerator, it is likely that thetemperature and humidity of the vegetable room 24 vary due to frequentdoor opening and/or varying environment. As a result, there maysometimes occur a considerable temperature difference between the coldspace 30 and the vegetable room 24 which would cause excessive coolingof the emitter electrode 52 to condense excessive amount of water oreven freeze the water. When this occurs, i.e., the temperaturedifference exceeds a critical level, the controller 76 responds toactivate the heating jacket 100 so as to heat the emitter electrode 52to the optimum temperature, thereby enabling to keep generating the mistsuccessfully. The optimum temperature and the critical level areconstantly updated at the controller 76 in consideration of varyingtemperatures of the cold space 30 and the vegetable room 24, and alsorelative humidity of the vegetable room 24.

FIG. 6 shows an atomizing unit 50 in accordance with a second embodimentof the present invention which is identical to the above embodimentexcept that the emitter electrode 52 is elongated to define at its rearend the cooling coupler 90A. The like parts are designated by likereference numerals, and no duplicate explanation is deemed necessary.The emitter electrode 52 extends through a cooling jacket 90B heldwithin the frame 80 to have its front end project out of the frame 80.The rear end of the emitter electrode 52, i.e., the cooling coupler 90Aprojects out of the cooling jacket 90B and the bottom wall 62 of thecasing 60 into an associated recess 48A in the surface of the partition44 for establishing a heat transfer relation with the cold space 30through the reduced-thickness portion of the partition 44. The coolingjacket 90B is made of a heat conductive metallic material into acylindrical shape surrounding the emitter electrode 52 within the frame80 or within the casing 60. Thus, the emitter electrode 52 is cooled bythe cold air in the cold space to condense the water thereon forgenerating the mist of the charged minute water particles. In thisembodiment, the cooling jacket 90B has a larger volume than the emitterelectrode to serves as a thermal accumulator for effectively cooling theemitter electrode 52. The present embodiment may be modified to includethe heating jacket 100 and the associated control as mentioned in theabove.

In the above embodiments and modification, the high voltage source 74 ispreferred to apply the high voltage to the opposed electrode 54 with theemitter electrode 52 being connected to the ground potential or nearground potential in order to keep the housing 20 of the appliance freefrom the high voltage. However, it may be possible to apply the highvoltage to the emitter electrode 52 relative to the opposed electrode54, for example, +5 kV to the emitter electrode with the opposedelectrode being connected to the ground potential, provided thatsufficient electrical insulation is made between the emitter electrodeand the housing of the appliance. In this instance, the condensed wateris atomized into positively charged minute water particles which aredischarged in the form of a mist in the vegetable room, i.e., thetemperature-regulated space, while at the same time positive dischargedfrom the emitter electrode are entrapped by the opposed electrode of theground potential to avoid the electrostatic shock, as is discussed withreference to FIG. 4.

1. A temperature-regulating appliance equipped with cooling means and an electrostatically atomizing unit, said appliance being configured to have a temperature-regulated space and a cold space divided by a partition, said temperature-regulated space being configured to have its temperature regulated by an air from said cold space cooled by said cooling means, said atomizing unit comprising: an emitter electrode being configured to condense thereon water from within the surrounding air when being cooled; a high voltage source being configured to apply a high voltage to the water on said emitter electrode to electrostatically charge the water for atomizing it into a mist of charged minute water particles; wherein said emitter electrode is configured to have its front end exposed to said temperature-regulated space and to have its opposite rear end held in heat transfer relation with said cold space through said partition so as to be cooled by said cold space for condensing the water on said emitter electrode, and said atomizing unit comprises a casing configured to accommodate the emitter electrode and the high voltage source, said casing having a front wall and a rear wall spaced from each other, and being mounted at its rear wall on said partition, said front wall being formed with an outlet for introducing the air from said temperature-regulated space and discharging said mist into said temperature-regulated space, and said emitter electrode being provided with a cooling coupler which projects out through said rear wall into said partition, only said cooling coupler projecting into said partition.
 2. A temperature-regulating appliance as set forth in claim 1, wherein said partition is formed partly with a reduced-thickness portion which receives a projecting end of said cooling coupler.
 3. A temperature-regulating appliance as set forth in claim 2, wherein said partition is formed in its surface with a recess which defines said reduced-thickness portion.
 4. A temperature-regulating appliance as set forth in claim 1, wherein said atomizing unit includes an opposed electrode held in an opposite relation with the front end of said emitter electrode, high voltage source being connected to apply the high voltage across said emitter electrode and said opposed electrode with said emitter electrode being connected to a potential nearer to a ground potential than said opposed electrode.
 5. A temperature-regulating appliance as set forth in claim 1, wherein said emitter electrode is held in heat transfer relation with a heating jacket which is configured to heat said emitter electrode, said atomizing unit includes a controller which is configured to detect a temperature difference between said cold space and said temperature regulated space and activate said heating jacket only when said temperature difference exceeds a predetermined threshold.
 6. A temperature-regulating appliance as set forth in claim 1, wherein said cooling coupler is surrounded by a frame.
 7. A temperature-regulating appliance as set forth in claim 1, wherein the rear end of said emitter electrode is embedded into said cooling coupler.
 8. A temperature-regulating appliance equipped with cooling means and an electrostatically atomizing unit, said appliance being configured to have a temperature-regulated space and a cold space divided by a partition, said temperature-regulated space being configured to have its temperature regulated by an air from said cold space cooled by said cooling means, said atomizing unit comprising: an emitter electrode being configured to condense thereon water from within the surrounding air when being cooled; a high voltage source being configured to apply a high voltage to the water on said emitter electrode to electrostatically charge the water for atomizing it into a mist of charged minute water particles; wherein said emitter electrode is configured to have its front end exposed to said temperature-regulated space and to have its opposite rear end held in heat transfer relation with said cold space through said partition so as to be cooled by said cold space for condensing the water on said emitter electrode, and said atomizing unit comprises a casing configured to accommodate the emitter electrode and the high voltage source, said casing having a front wall and a rear wall spaced from each other, and being mounted at its rear wall on said partition, said front wall being formed with an outlet for introducing the air from said temperature-regulated space and discharging said mist into said temperature-regulated space, said emitter electrode being configured to project its rear end out through said rear wall into said partition.
 9. A temperature-regulating appliance as set forth in claim 8, wherein said emitter electrode is surrounded by a cooling jacket, said cooling jacket having a larger volume than said emitter electrode and being disposed within said casing.
 10. A temperature-regulating appliance as set forth in claim 9, wherein said cooling jacket is surrounded by a frame.
 11. A temperature-regulating appliance as set forth in claim 8, only said emitter electrode projecting into said partition. 